月: 2023年1月

What Is a Generator?

Generators convert mechanical energy into electrical energy.

While there are generators for both AC and DC power, “generator” typically refers to those for AC power, which are globally used as commercial power sources.

Featuring one or more rotating shafts, generators transform externally applied mechanical energy into electrical energy. The conversion efficiency varies: the more electrical energy consumed, the more mechanical energy is required, making the shaft harder to turn. Conversely, with minimal energy consumption, the shaft rotates freely.

Uses of Generators

Generators find applications across industries and households.

Home electricity often originates from power companies’ synchronous generators, which are versatile, operating on thermal, nuclear, or hydroelectric power.

Recently, wind power generators, a renewable energy source, have popularized induction generators due to their simplicity. Additionally, diesel generators serve as emergency power sources in homes, highlighting the ubiquity of generators wherever AC power is needed.

Principle of Generators

Generators are principally categorized into synchronous and induction types. The simpler induction generators require at least one synchronous generator in the system for operation.

1. Synchronous Generators

These generators, equipped with an excitation device such as a permanent magnet, generate electricity by varying the magnetic field’s relation to the windings over time. The power generation voltage and frequency depend on the number of poles and rotation speed.

2. Induction Generators

Operating on electromagnetic induction, these generators need no excitation device. They function as motors when connected to a power system and become generators when attached to a turbine or windmill and rotated at or above synchronous speed.

Types of Generators

Generators are classified into four types based on the fuel used.

1. Diesel Generators

These generators, connected to a diesel engine, compress air, heat it, and inject fuel for combustion to generate electricity.

2. Gasoline-Powered Generators

Notable for their portability, these generators come in various models and types.

3. Gas-Powered Generators

Available in cassette gas and LP gas models, these generators cater to different needs.

4. Inverter Generators

These are equipped with inverters or cyclone converters for stable, high-quality electricity suitable for sensitive devices.

How to Choose a Generator

Selecting a generator involves considering its type, each with unique advantages and limitations.

1. Diesel Generators

Characterized by high output and stability, these generators are less suitable for residential use due to noise, vibration, and emissions but offer low running costs.

2. Gasoline-Powered Generators

They operate quietly and are relatively affordable.

3. Gas-Powered Generators

Cassette gas models are portable, while LP gas models suit commercial use.

4. Inverter Generators

Inverter models provide high-quality electricity for precision equipment, with non-inverter models being more common due to minimal electricity loss.

Generator Structure

Generators are differentiated by their power generation mechanism into DC, AC, and 3-phase AC types.

1. DC Generators

These generate direct current when a coil between magnets is rotated, useful in compact emergency equipment.

2. AC Generators

With fixed coils and rotating magnets, these are suitable for home appliances and compact generator designs.

3. Three-Phase AC Generators

Featuring three coils installed at 120° intervals, these generators are ideal for high-voltage, high-current applications, such as in power plants.

What Is a Foam Resin?

Foam resin, a synthetic resin infused with gas to create a foam-like structure, is integral to manufacturing a wide range of products. It encompasses materials used in both the initial stages of semiconductor fabrication, such as wafers and photomasks, and subsequent packaging processes involving molds, bonding wires, and encapsulants.

Uses of Foam Resins

These versatile materials are employed in various applications, from automotive components like seat cushions and bumpers to housing for electronic instruments with complex shapes. Their high rigidity and design flexibility make them suitable for both interior and exterior parts, enhancing both functionality and aesthetics.

Principle of Foam Resins

Foam resins work by absorbing internal stress and using gas pressure to maintain contact with the mold, reducing warpage and material use through an internal air layer. They can be created through chemical or physical foaming processes, with adjustments made to prevent surface defects like swirl marks.

Types of Foam Resins

• Rigid and Flexible Polyurethane Foam: Offers high compressive strength and flexibility. Used in a variety of applications based on their chemical structure and resistance properties.
• Polystyrene Foam: Known for its lightweight, heat insulation, and shock-absorbing capabilities.
• Polyethylene Foam: Features low water absorption and high secondary processability, suitable for a wide temperature range.
• Polypropylene Foam: Challenges in foam wall formation due to rapid viscosity changes, but offers high heat resistance.
• Phenolic, PET, Cross-Linked EVA, and Other Foam Resins: Each brings unique properties, from thermal decomposition to high elasticity, serving diverse industrial needs.

What Is a Soldering Iron?

A soldering iron is a tool used for soldering metal-to-metal joints such as the legs of electronic components and the wiring on a circuit board.

It has a simple structure with a plastic handle attached to a metal part that heats and melts the solder. In soldering, an alloy layer is created between the metal to be joined and the solder, where the metal and solder fuse together.

The purpose of the soldering process is primarily to allow electricity to pass through the connected metal parts. Therefore, it is not required to be as strong as welding operations. Solder has a low melting point for a metal, so the soldering iron does not melt the metal of the electronic components and wiring.

Another advantage is that once wiring is done, it can be modified by reheating the solder.

Uses of Soldering Irons

Soldering irons are used for wiring electronic components at manufacturing and production sites and for electrical wiring and repairs in general households. There are two types of soldering irons: ceramic heaters and nichrome heaters.

1. Ceramic Heater

Ceramic heaters consist of a tungsten heater encased in ceramic, which heats the tip from the inside. It takes a short time to reach the proper soldering temperature and has excellent insulation properties, making it suitable for wiring ICs and other delicate electronic components. 

2. Nichrome Heater

A nichrome heater is a type of soldering iron that heats from the outside by wrapping a nichrome wire around the tip. Because it is inexpensive, it is suitable for simple electrical wiring and repair work at home or for learning.

Principle of Soldering Irons

When using a soldering iron, first contact the soldering iron tip with a joint point, such as the foot of a device, to heat the metal part so that the Soldering Iron can easily blend with it. At this point, the larger the area of direct contact between the iron tip and the metal part, the more efficient the heat is transferred.

If the tip size is small, heat is not transferred well and work efficiency is reduced. On the other hand, if the tip is larger than the area to be joined, it may damage other areas than the metal part, so care must be taken.

Once the soldering iron has sufficiently warmed up the metal to be joined, press the tip of the soldering iron against the metal while keeping the soldering iron tip on the metal part. The solder will melt immediately and spread over the warmed metal. When the solder is spread over the metal and slightly raised, release the solder, then the Soldering Iron. This step creates an electrical connection between the metal joints.

Soldering Structure

Soldering is a welding process used to wire components within electrical and electronic circuits. The priority is on the performance of the connection when energized rather than on fixing things in place. Soldering uses the phenomena of “wetting” and “capillary action” to weld.

Wettability means, for example, that when a drop of water is dropped on glass and metal, it spreads thinly on the glass and becomes a sphere on the metal. This is because the rate of adhesion to the glass is greater than the cohesive force of water molecules, and this state is called wetting. This state is called wetting. In order for the solder to blend well with the base metal, this wetting must occur in order to weld properly.

The other is capillary action, which is the penetration of liquid into narrow gaps. In soldering, penetration of molten solder into the base metal into the gap is an important factor that determines the finished product.

Other Information about Soldering Irons

1. Difference Between Soldering and Brazing

Soldering is classified as brazing in welding. Similar to soldering is what is called brazing. This is also a welding method classified as brazing. The joining principle is exactly the same, but the performance requirements and tools for the joint are different.

The temperature is classified according to the melting point temperature of the soldering material (solder or brazing material), with brazing being considered being higher than 450°C and soldering lower than 450°C. In actuality, however, the temperature is actually around 450°C. In reality, however, there are few solder materials with melting points in the vicinity of 450°C, and there is no clear reason for this classification.

2. Lead-Free Solder

Traditionally, solder was made of an alloy of lead and tin, but since 2000, environmentally friendly lead-free solder has become the mainstream. Lead-free solder has a higher melting point and lower fluidity than conventional solder, making soldering a hotter and more time-consuming process.

Therefore, when using lead-free solder, a ceramic-heated soldering iron with excellent insulation and thermal conductivity is suitable.

What Is a Semiconductor Material?

Semiconductor materials encompass all substances used in creating semiconductor devices, ranging from wafers, which form the chip’s main body, to photomasks, gases for etching and cleaning, and components for chip packaging. Wafers are central to semiconductor material, usually referring to silicon or compound semiconductors like silicon carbide (SiC) and gallium nitride (GaN).

Uses of Semiconductor Materials

These materials find applications across various fields, notably in producing electronics such as low-cost silicon-based devices, high-frequency gadgets, LEDs, and optical communication tools. Their diverse functionalities stem from the distinct properties of single-element and compound semiconductors.

Principle of Semiconductor Materials

The manufacturing process begins with the refinement of silicon into high-purity polycrystalline silicon. This material then undergoes a single-crystal pulling process to form single-crystal ingots, which are subsequently sliced into wafers and polished for use in semiconductor devices.

Types of Semiconductor Materials

Semiconductors are categorized based on their integration level into discrete semiconductors, integrated circuits (ICs), and large-scale integrated circuits (LSIs), each serving different functions in a myriad of applications from automotive to personal computing devices.

• Discrete Semiconductors: Basic devices performing single functions, like diodes and transistors.
• IC (Integrated Circuit): A step up in complexity, integrating multiple elements for broader functionalities.
• LSI (Large Scale Integration): High-integration devices combining numerous components for complex functions, crucial in modern electronics.

What Is a Conveyor System?

A conveyor system is a system that automatically transfers goods, parts, etc. They are effective for transporting heavy items that are difficult to move by hand, at sites with large quantities of items to be transported, or at sites with complex conveyance lines.

Various forms of equipment are available for conveyor system, including belt and chain conveyors, overhead conveyor system, and lifting equipment. Furthermore, conveyor robots, automatic guided vehicles (AGVs), and picking equipment can be combined to automate conveyance, reducing costs through labor and manpower savings and improving the efficiency and quality of conveyance operations.

Uses of Conveyor Systems

Conveyor systems are widely used in the manufacturing and logistics industries.

In the logistics industry, they are used at sites where goods stored in warehouses are shipped. The system combines automated warehouse systems, sorting equipment, picking equipment, and other peripheral equipment to achieve a system that matches the characteristics of the products and the environment of the warehouse.

In the manufacturing industry, they are used to transport parts, intermediate products, etc. between factory processes, and to distribute final products in warehouses. In the automotive industry, in particular, these systems are indispensable for transporting large parts such as bodies and tires, as well as intermediate products during manufacturing.

Features of Conveyor Systems

Most types of conveyors consist of systems in which a belt or chain is slowly rotated by a motor to convey loads on the belt.

Resins such as polyurethane and Teflon are often used for the belt material, while leather, woven fabric, rubber, and steel are also used. Depending on the cargo to be conveyed, the conveyor belts may require oil resistance, heat resistance, anti-static properties, and other characteristics.

For the shape of the belt, flat belts or mesh belts are used when the cargo to be conveyed is sand, cement, grains, food products in the process of manufacturing, etc. in bulk, while rough top belts or roller belts with uneven surfaces are used when the cargo is packaged in containers such as boxes or bags. If the conveyor is inclined at an angle, belts with fins are used to prevent the material from sliding downwards.

Overhead conveyor systems are systems in which conveyor equipment automatically runs on rails installed in the ceiling and moves up and down at target points to transport goods. Since these systems makes effective use of factory space, they is used for transporting parts and products at manufacturing sites.

What Is a Flat Spring?

A flat spring is a spring material in the form of a thin plate. It is used to push or pull a plate material within its elastic range, and the main materials used are iron, steel, stainless steel, and copper. Various bending strengths can be produced by using not only the material but also the plate thickness and shape, and by changing the bending process and dimensions according to the application.

Types of flat springs include not only thin plate springs consisting of only one plate, but also stacked plate springs consisting of several plates. A circular flat spring is also a type of flat spring, and a spiral spring such as a spring is also classified as a flat spring.

Uses of Flat Springs

Flat springs are used in a wide range of applications, including industrial equipment, automobiles, aircraft, space satellites, medical equipment, construction hardware, and toys, and thus play an important role in our daily lives.

Flat springs have three main uses: as shock absorbers using elasticity, for restoration using restorative force, and for fastening, using elasticity to hold objects in place. In addition to these, they are sometimes used as electrical contacts utilizing the conductivity of metals.

Principles of Flat Springs

Flat springs are thin sheets of metal or other material that are used to apply a load within their elastic range. They can be formed by laser cutting, cutting with a turret puncher, or bending with a press brake. Therefore, unlike coil springs, there are fewer restrictions on the shape and size, and it is possible to create a product that matches the application and the location of use.

The stress and amount of deflection when a load is applied to flat springs can be calculated. Therefore, in order to use and shape flat springs in appropriate locations, allowable stress and deformation must be calculated at the time of design. However, the more complex the shape of flat springs are, the more its characteristics are likely to change depending on the shape, fixing method, and direction of load application, and the larger the potential error in the calculation results on the table becomes. Flat springs with complex shapes require not only simulation by calculation but also quality evaluation on prototypes. However, since some flat springs are an important part that often cannot be manufactured cost-effectively, it is desirable to use similarly shaped flat springs for parts that can be used, and it is important to accumulate accurate design data before production.

What Is a Surface Mount Device (SMD) LED?

A Surface Mount Device (SMD) Light Emitting Diode (LED) is a type of LED device package that is mounted by soldering directly to a pattern on a printed circuit board without any insertion holes on the board.

In addition to the top-emitting type, there is also a side-emitting type that emits light from the side.

Compared to the old bullet-type LED packages, surface-mount LEDs are brighter and provide a wider illumination angle, are smaller, require less mounting space, and have higher heat dissipation efficiency due to the material and structure on the back of the element.

Uses of SMD LEDs

SMD LEDs are used in most general lighting fixtures such as ceiling lights, indirect lights, desk stands, and sensor lights because of their brightness and ability to illuminate a wide area.

They are also used in control panels and remote controls for digital cameras and video cameras because they can be mounted on the surface of the product.

SMD LEDs are also used in a wide range of other applications, such as automobile headlights, room lights, meters and other panels, LCD TV and LCD display backlights, and electric decorations.

Principle of SMD LEDs

SMD LEDs consist of 0.3mm square LED elements fixed to a lead frame, LED elements, and electrodes connected with bonding wire, and then encapsulated with resin such as epoxy or silicon.

Transparent epoxy or silicon resin is used as the encapsulating material to allow the light emitted by the LED elements to shine out of the package, but recently glass materials have also been used.

Silicon resin is used for LEDs for high-power products such as lighting fixtures and LCD backlights because of its slower rate of light transmittance degradation due to deterioration. Epoxy resins, which are said to degrade more quickly than silicone resins, are used in LEDs for low-power products such as indicators. Glass materials degrade even more slowly than silicone resins and have high reliability.

SMD LEDs are often used for general lighting applications, but lighting requires white light. Therefore, SMD LEDs for lighting purposes have a mechanism to obtain white light by mixing light from single-color LEDs. The main methods of producing white light are as follows:

Single-chip method: This method combines a blue LED with a yellow phosphor that emits yellow light when excited by blue light. Since blue and yellow are complementary colors, mixing them produces light that is perceived as white by the human eye. Because of its simple structure and high efficiency, this method is currently the mainstream. Another method is to combine blue LEDs with red and green phosphors to mix the three primary colors of light to obtain more natural white light.

Multi-chip method: This method combines blue, red, and green LEDs, which are the three primary colors of light, and requires a more complex circuit configuration because the lighting voltage varies depending on the LED color.

What Is an Engine Lathe?

A lathe is a type of machine tool for metalworking. The workpiece is fixed to a rotating base called a chuck. A cutting tool called a bite is applied to the workpiece to cut it into the desired shape.

There are various types of lathes, of which the most basic is the engine lathe. Generally, the word “lathe” means an ordinary engine lathe.

An engine lathe consists of parts including a spindle head, bed, tailstock, feeder, and reciprocating table. The shaving process, which involves applying a tool to the workpiece, can be done by hand. By changing the type of byte, various types of machining can be performed with a single machine.

Uses of Engine Lathes

Lathes are used for processing cylindrical or bar materials, as they rotate and sharpen the workpiece. In lathe turning, the workpiece is made symmetrical to the axis of rotation, so lathes are used for machining to create cylindrical or conical shapes, threading, and other operations.

In factories and other workplaces, numerically controlled (NC) lathes are most widely used, as they perform machining automatically by numerical control. However, engine lathes are suitable for complex and difficult processing that NC lathes cannot handle, as well as for small-lot processing such as prototypes and custom-made products.

In addition, since the use of an engine lathe enables a good understanding of lathe principles, they are widely used for educational and practical training purposes at technical high schools and vocational schools.

Features of Engine Lathes

Engine lathes consist of a spindle head, bed, tailstock, feeder, and reciprocating table.

The spindle head is equipped with a spindle and motor that rotates the workpiece, a spindle speed converter, and a start lever. The spindle is equipped with a chuck that holds the workpiece. The chuck grips the workpiece in a mechanical, magnetic, or vacuum type. However, the most common type is the mechanical type.

The tailstock is a movable stand installed on the opposite side of the spindle head and can be fixed in position according to the length of the workpiece. A support center can be set on the axis of the tailstock to support the workpiece or a drill can be set for drilling.

The reciprocating table is located between the spindle head and the tailstock and consists of a saddle, an apron, and a tool rest to mount a tool. The feed unit is located on top of the reciprocating table and feeds the tool post vertically or horizontally.

The bed is the main body of the lathe and supports the spindle head, tailstock, reciprocating table, and other devices. Since large cutting resistance is generated during cutting, the bed must be rigid enough to withstand such resistance. In addition, vibration caused by the motor must be suppressed in order to improve machining quality.

Machining operations that can be performed with engine lathes include external rounding to cut the outside of a workpiece into a cylindrical shape, tapering to make the workpiece conical, plunge cutting to separate the material, boring to machine the inside of a cylinder and thread cutting.

What Is an Oil Skimmer?

A floating oil skimmer is a device to recover unwanted oil (floating oil) from water-soluble coolant used as cutting oil in machine tools such as lathes and milling machines. It is also called an oil skimmer.

Floating oil includes lubricating oil and hydraulic oil, which can cause coolant rancidity and foul odors.

The use of an oil skimmer will recover the oil that causes these problems, thereby extending the life of the cutting tool.

There are two types of oil recovery methods: the belt type and the screw type, with the belt type being more commonly used today.

Uses of Oil Skimmers

Oil skimmers are mainly used in coolant tanks of machine tools for cutting and in drainage tanks in factories.

Since hydraulic oil and lubricating oil tend to get mixed in with the coolant during the machining process, the oil must be removed frequently to keep the coolant clean.

Oil can also contaminate the water discharged from the factory. If these are released into the environment, they can be a serious cause of environmental pollution.

Oil skimmers can be used to clean wastewater and help prevent environmental pollution.

Principle of Oil Skimmers

Floating oil gradually accumulates in the coolant reservoirs used in machine tools.

This floating oil can cause coolant rancidity and foul odors, which can lead to deterioration of work environment safety as well as contribute to environmental pollution due to wastewater.

Floating oil skimmers must be used to remove the floating oil.

Oil skimmers are classified into belt-type and screw-type depending on the oil skimming method.

Belt-Type Oil Skimmers

In the belt-type, a rotating plastic or steel belt is installed in the storage tank, and the liquid adhering to the belt is discharged into a separate tank (separation tank).

The discharged liquid is separated into oil and water in the separation tank, and only the surface floating oil is discharged through the collection port, leaving coolant in the small tank.

Screw-Type Oil Skimmers

In the screw-type, a screw with a special helical structure is rotated to collect oil.

By utilizing the difference in viscosity between aqueous solution and oil, only oil with high viscosity adheres to the screw.

Unlike the belt-type, this system does not require a tank for separating coolant and oil.